Telephone



(NoModeL) T. A. WATSON.-

Telephone. v No. 231,739. ,7 Patented Aug. 31,1880.

\X/tIT EEEE 5. Irlxfz r l nf NrrED STATES FFIQE.

PATENT TELEPHONE.

SPECIFICATION forming part of Letters Patent No. 231,739, dated August 31, 1880.

Application filed June 15, 1880.

To all whom it may concern:

Be it known that I, THOMAS A. \VATSON, of Everett, county of Hiddlesex, State of Massachusetts, have invented an Improvement in Telephone-Vibrators, of which the following description, in connection with the accompanying drawings, is a specification.

My invention relates to telephones, and has for its object to make the vibrations of the part causing electric pulsations of greater amplitude than those of the usual diaphragm or body set in vibration by the usual sound-waves.

Numerous devices havebeen tried, with more or less success, for mechanically increasing the amplitude of vibrations, and consequently the volume of sound; but these devices have usually involved the use of joints or mechanical connections in which there is always more or less lost motiona serious and sometimes fatal obstacle to the proper operation, owing to the exceeding minuteness of the normal movements caused by the sound-waves of articulate speech.

The invention is herein shown embodied in a magneto-telephone; and it consists in connectin g with a diaphragm one end of a flexible vibrator consisting of a band or strings, so that the said diaphragm, in vibrating, causes variations in thelongitudinal strain or tension of the said band, herein shown as a series of wires pa-ssin g with considerable tension through the magnetic field, and forming the armature of a magnet provided with the usual induction-coils. By the use of a large number of wires passingthrough the field of the magnet the magnetic force is more widely distributed. The lateral vibrations of the wires caused by thismethod will be of greater amplitude than those of the connected diaphragm, upon the principle of the toggle joint, the said diaphragm producing primarily variations in 1011- gitudinal strain on the said wires, and thus causing an oscillation or lateral vibration thereof much greater in extent than the longitudinal movement.

Figure 1 is a side elevation of a telephone embodying 1n y invention the inclosin g-case bein g removed; and Fig. 2, a plan View thereof.

The magnet a, supported on the frame work I), and provided with the pole-pieces c and induction-coils d, may be of any usual construction.

(No model.)

The diaphragm e in front of the mouth-piece f may be of any desired material, and has connected with it a series of wires, g, of soft iron or other suitable magnetic material to form an armature, stretched through the magnetic field close to, but not in contact with, the poles of the magnet, and connected with a straining-bar, 4h, providedwith a screw, '5, passing through a standard, m, on the frame-work b.

The tension of the wires 9 collectively may be varied and adjusted by athumb-nut, n, on the screw 1'.

The vibrations imparted to the diaphragm 6 by sound-waves entering the mouth-piece f will cause variations in the longitudinal strain on and consequent tension of the wires g, and as they will normally be drawn slightly out of a straight line by the lateral attraction of the magnet, and by gravitation when they are not vertical, the said changes of tension willeause lateralvibrations or oscillations of the said Wires of an amplitude greater than that of the diaphragm itself, the increase of movement being the same as that shown in a toggle jointed lever when the two parts connected by the joint are coming into a line with one'another.

The flexibility of the stretched armature is the equivalent of the toggle-jointed lever as far as the relation of the lateral to the longitudinal movement is concerned, but it is free from the objections hereinbefore mentioned existing in any devicein which separate parts are connected by a movable joint.

As the said wires forming the armature of the magnet pass through and occupy the greater portion of the magnetic field, the said vibrations will cause strong electric waves in the induction-coils d and electric circuit.

While a magneto-telephone constructed on this plan gives especially good results as a transmitting-instrument, it is also well adapted for use as a receiver.

It is obvious that the flexible stretched vibrator g, set in vibration on the toggle-joint principle by the diaphragm connected therewith, may be used in other instruments besides the magneto-telephone herein shown.

The wires g need not be all arranged in one plane, as shown, but may be distributed all around the poles'of the magnet to completely fill the magnetic field.

I am aware that a vibrator has been used consisting of a series of wires placed above the poles of the magnet; but these were not connected to a diaphragm and vibrated longitudinally thereby, as herein shown, but were vibrated laterally by the direct impact of the sound-waves, no increase in amplitude or eX- tent of vibratory movement being attained by such construction.

I claim' 1. The herein-described method of increasin g the amplitude of vibrations resulting from sound-waves, which consists in connecting the primary vibrating point with one end of a flexible vibrator, whereby the primary vibrations will cause variations in longitudinal strain on the vibrator, and tln-webyproduce lateral vibrations in thesaid vibrator of greater amplitude than the primary vibrations, substantially as described.

2. In a telephone, a magnet and its induction eoil, a diaphragm, and a flexible armature connected therewith and stretched therefrom through the magnetic field of the said magnet, whereby the vibrations of the said diaphragm cause variations in tension and consequent lateral vibrations of increased amplitude in the said flexible armature, substantially as described.

3. A diaphragm and flexible band or string connected therewith and stretched therefrom, and caused to deviate from a rectilinear course, whereby the said diaphragm, in vibrating, causes variations in longitudinal strain or tension of the said flexible band or string, and thereby puts it in lateral vibration to cause fluctuations in an electric current, as and for the purpose described.

4. In a magneto-telephone, a magnet with its induction-coils, and a diaphragm and series of wires stretched therefrom through the magnetic field of the said magnet, combined with an adjusting device to adjust the normal longitudinal strain of the said wires, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

THOMAS A. WATSON.

Witnesses:

J 0s. P. LIVERMORE, N. E. (l. WHITNEY. 

